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HAT-P-12 b Transit (2019-02-26)

HAT-P-12 b exoplanet (Canes Venatici)

HAT-P-12 b, discovered by Hartman et al, 2009   http://adsabs.harvard.edu/abs/2009ApJ...706..785H is an exoplanet that orbits the star HAT-P-12 approximately every 3.21 days The image below was taken whilst HAT-P-12 was undergoing a transit by the exoplanet and is part of a series of images that taken together show a small but diagnostic reduction in the brightness of the host star during the transit. Mass 0.211 MJupiter,  radius of 0.959 RJupiter , mean density of 0.295 g cm-3. Period = 3.2130598 ± 0.0000021 d, transit epoch Tc = 2454419.19556 ± 0.00020 (BJD) HAT-P-12 lies at a distance 464 light years (142.5 parsecs), is K4 Dwarf with mass 0.73 Msun

Annotated CCD Image (70% size) 10 x 30s exposure (average combine), 3x3 binning, Xo Filter 2019-02-27 01:03 UT (#669402-11) 12" LX200R (at f/10.4) + ST-10XME Auto-guided using TS 80mm APO, ZWO ASI178MC & PHD2

Summary Light Curve showing transit of HAT-P-12b 2019-02-27 00:03 to 02:23 UT Data collected (420 x 30s frames) demonstrate a clear dip in the brightness of host star HAT-P-12 that corresponds with the forecast time and depth of the transit by exoplanet HAT-P-12 b. (timings from Transit Finder Tool on  https://astro.swarthmore.edu  )

Detailed Light Curve showing transit of HAT-P-12b 2019-02-27 00:03 to 02:23 UT with various environmental & supporting information

420 x 30s frames collected between 2019-02-26 23:40 & 2019-02-27 03:53 UT (JD  2458541.49 - 2458541.66) Images taken through an Astrodon Exoplanet Blue Blocking (BB) Filter, and reduced using the appropriate Master Dark  and Master Flat Frames [ Master.-20c_3x3_030s.S660.AvMedian17.ST10.DARK.FIT & MasterFlat.3x3.Xo.S629.SkyFlats.AvMedian15.FIT] Photometry using 3 calibration stars (C1 to C3) based on AAVSO's Photometry Sequence for HAT-P-12 (see details below) Differential Magnitudes for HAT-P-20 are zero based using average calculated magnitude from the interval (02:30-03:53) that followed the transit Differential Magnitudes for Check Star are  zero based using average calculated magnitude  from the entire run and are shifted by +0.10mag for display 5 min moving average of Differential Mags are displayed for both HAT-P-12 and theCheck Star. No (V+R) magnitude data was available for the BB (Blue -Blocking) filters used and therefore V Magnitude where used instead for the calibration. (This is likely to make the calculated magnitude slightly off the HAT-P-12's true V mag,  but differential magnitudes should still be good) SNR, Ambient Temperature and Altitide data is shown in the graph for information. (note that altitude varied from 51 to 76 over the course of the observing run) Raw Magnitudes & SNR measured using AstroMain/VMA and CCDSoft.  Calibrated Magnitudes and Differential Magnitudes calculated usin MS Excel (also used for graphing the results)

Image of HAT-P-12 Showing Calibration Stars (C1-C3) and Check Star (K) used for photometric analysis of HAT-P-12  HAT-P-12 (GSC 3033:706) :  V Mag +12.84,  AUID 00-BKN-997 C1 (GSC 3033:996): V Mag +13.130 (0.025) , AUID 000-BLT-550 C2 (GSC 3033:872): V Mag +13.314 (0.031), AUID 000-BLT-551 C3 (GSC 3033:978): V Mag +12.924 (0.039), AUID 000-BLT-549 K (GSC 3033:754): V Mag +13.939 (0.035),  AUID 000-BLT-542 (C1-C3 and their magnitudes are chosen from the AAVSO's Field Photometry for HAT-P-12 (Sequence Magnitudes Source  is APASS

Annotated CCD Image (70% size) Taken through Astrodon Exoplanet Blue Blocking (BB) Filter 25 x 30s exposure (average combine), 3x3 binning, BB / Xo Filter 2019-02-26 23:48 UT (#669271-95) 12" LX200R (at f/10.4) + ST-10XME Auto-guided using TS 80mm APO, ZWO ASI178MC & PHD2

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XO-2b Transit  (2009-11-08)

XO-2b Transit,  2009-11-08  Normalised Differential Magnitudes Time Series graphs showing normalised differential magnitudes  (exaggerated scales) Blue dots are data values associated with individual frames whilst yellow dots are a moving average  Whilst data scatter (+/-0.032m to +/-0.018m) is larger than the expected  transit depth (0.015 mag),  the overall dip in XO-2 brightness through the transit window is still noticeable. Notes describing the preparation, recording and analysis of the XO-2b Exoplanet Transit

XO-2 / GSC 3413:0005   (Lynx) with comparison/check stars

Annotated CCD Image (full frame) 25 x 15 sec exposure (average combine), 3x3 binning, V Filter  2009-11-08 18:53 h UT  (#397043-67) 12" LX200R  (at f/5.7) + ST-10XME

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HD 209458b Transit - attempt (2005-08-08)

Transit Detection Attempt, 2005-08-08
- 4h 20m session attempting to record the transit of extra solar planet HD 209458b across its sol HD 209458 (Osiris)
- 552 images were recorded over a period of 3h 50m  (15 sec exposures through V filter)
- Inconsistent sky conditions and deteriorating sky conditions with cloud after 01:00 h UT reduced data quality.
 A description of the attempt and results has been compiled. 
- Analysis suggests an overall dimming of ~ 0.01 mag during the time of the transit, but this is unfortunately within the 
uncertainty range of the measurement (typically +/- 0.01 to +/- 0.02 mag). Detection of the dimming event was also compromised by having insufficient data prior to ingress and deteriorating sky conditions around the time of egress. 
| Dry Run Analysis 2004-08-20 | Transit Analysis 2005-08-08 |

Graph showing differential magnitudes for HD 209458  (Corrected for B-V colour difference between HD 209458 and Comparison Star)

Graphs shows points representing the average differential magnitude  in each 5 min period. High/Low lines are plotted at +/- 1 S.D.  Data may possibly shows an overall dimming of ~ 0.01 mag during  the time of the transit, but this is unfortunately within the  uncertainty range of the measurement (typically +/- 0.01 to +/- 0.02 mag). Detection of dimming is also compromised by having insufficient data prior to ingress and deteriorating sky conditions with cloud around the time of egress.

Example V Filter image of HD 209458 HD 209458 (V), HD 209346 (C), GSC 1688:1766 (K)

Annotated CCD Image 15 sec exposure (V filter) 2005-08-05  22:30h UT(#91090)

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